This disclosure relates to processes for preparing toner compositions. More specifically, continuous processes for emulsion polymerization, aggregation, coalescence, washing and wet sieving are described. These processes can be used to produce toner compositions.
Processes for forming toner compositions for use with electrostatographic, electrophotographic, or xerographic print or copy devices have been previously disclosed. For example, toners can be prepared by a process that involves emulsion preparation, followed by aggregation and coalescence of the emulsion, washing the resulting product and then isolating the toner. Such processes for the preparation of toners are illustrated in a number of patents, such as U.S. Pat. Nos. 5,290,654; 5,278,020; 5,308,734; 5,370,963; 5,344,738; 5,403,693; 5,418,108; 5,364,729; 5,346,797; 5,348,832; 5,405,728; 5,366,841; 5,496,676; 5,527,658; 5,585,215; 5,650,255; 5,650,256; 5,501,935; 5,723,253; 5,744,520; 5,763,133; 5,766,817; 5,747,215; 5,827,633; 5,853,944; 5,804,349; 5,840,462; 5,869,215; 5,863,698; 5,902,710; 5,910,387; 5,916,725; 5,919,595; 5,925,488 and 5,977,210, the entire disclosures of each of which are incorporated herein by this reference.
Currently, one or all of the emulsion, aggregation, coalescing, washing and isolation processes are performed in a batch mode. Accordingly, because each individual batch process involves the handling of bulk amounts of material, each process takes many hours to complete before moving to the next process. In addition, batch-to-batch consistency is frequently difficult to achieve because of variations that may arise from one batch to another.
It would be advantageous to provide a process for the preparation of toner that is more efficient, takes less time, and results in a consistent toner product.